clk: microchip: fix criticality of peripheral clocks on mpfs

Sync the critical clocks in the U-Boot driver with those marked as
critical in Linux. The Linux driver has an explanation of why each clock
is considered to be critical, so import that too.

Fixes: 2f27c921 ("clk: Add Microchip PolarFire SoC clock driver")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>